A. Technical Field
The present invention relates generally to screen systems for limiting the movement of insects, and more particularly, to a screen system that permits movement of insects in one direction through the screen but limits movement of insects in a second direction through the screen.
B. Background of the Invention
Many different systems are known for limiting the exposure of humans and animals to insects and other pests. One common type of system is a mesh screen that provides openings that allow light and air to pass but are too small to allow insects to pass. These screens are extremely effective in many environments, such as window openings, patios, tents, and the like.
However, one shortcoming of such conventional screens is that where the environment includes openings such as doors or flaps large enough for humans to pass into or out of the screened area, opportunities exist for the entry of insects if those openings are not promptly secured.
For example, if a child leaves a screened-in patio door open, insects can freely enter through that door opening until the door is once again closed. In many recreational applications, such as in boats, tents, and the like, frequent use of doorways, companionways, and flaps can lead to the entry of numerous insects. As to those insects, the screen now is counter-productive in that it keeps such insects inside the area, where they are not wanted.
In other applications, screens are erected to enclose areas that may already have insects within them. For instance, screened outdoor "rooms" with waterproof tops, screened sides, and no floors are commonly erected on residential lawns, where undesirable insects are present both in the air and in the grass.
Accordingly it is desirable to provide a screen system that limits the entry of insects to an area enclosed by the screen system yet permits insects already in that area to escape.